Search

The macrophage inducible C-type lectin (Mincle) is a pattern recognition receptor that recognizes trehalose dimycolate (TDM), and trehalose dibehenate (TDB) and related trehalose diesters, and thus represents a promising target for the development of vaccine adjuvants based on the trehalose glycolipid scaffold. To this end, we report on the synthesis of a series of long-chain α-branched, β-modified trehalose monoesters and diesters to explore how glycolipid structure affects signaling through Mincle. Key steps in our synthetic strategy include a Frater-Seebach α-alkylation to install the C20 aliphatic lipid on a malic acid derivative, and the formation of a β,γ-epoxide as an intermediate from which modifications to the β-position of the lipid can be made. Biological evaluation of the derivatives using nuclear factor of activated T cells (NFAT)-green fluorescent protein (GFP) reporter cell lines expressing mMincle or hMincle revealed that the hMincle agonist activity of all diesters was superior to that of...

We developed an ink-jet printing method for fabricating inorganic microdisks at room temperature, which is much lower than the melting point of solid-state inorganic oxide, and have fabricated an organic-inorganic hybrid microdisk laser. Silica was used as the inorganic disk material, and microdisk-shaped aggregates were formed by the ink-jet printing method using a solution in which nanosilica particles were dispersed in propylene glycol monomethylether (PGME) solvent. Then, a microdisk capable of laser oscillation was also prepared by preliminarily adding the laser dye rhodamine 6G to the ink to form a mixed organic material. The structural evaluation of the printed microdisk was first conducted using an optical microscope, a scanning electron microscope (SEM), and an atomic force microscope (AFM). The results of laser oscillation evaluation by optical excitation showed that the printed microdisk sufficiently functions as an optical resonator with a low optical loss. In these evaluations, excellent values such as a surface roughness of 5.83 nm from root mean square (R. M. S.) which is one forth smaller than the particle diameter, and a laser oscillation threshold of 4.76 µJ/mm2 at a wavelength of 601.4 nm were obtained. To the best of our knowledge, this is the first time that an inorganic microdisk has been fabricated at room temperature to realize an organic-inorganic hybrid microdisk laser.

We experimentally demonstrated the fabrication and the fundamental lasing evaluation of a printed microdisk cavity by focusing on a fluorinated spherical polymer FZ-001 to achieve a microdisk with small absorption loss in the visible range.

The relative proportion of kynurenine aminotransferase (KAT) I-IV activities in the brain is similar between humans and rats. Moreover, KAT II is considered to be the main enzyme for kynurenic acid production in the brain. Taken together, human KAT II knock-in (hKAT II KI) rats will become a valuable tool for the evaluation of KAT II targeted drugs as a human mimetic model. Although we initially tried the approach by conventional gene-targeting via embryonic stem cells (ESCs) to generate them, we had to give up the production because of no recombinant ESCs. Accordingly, we developed a method to improve the efficiency of homologous recombination (HR) in ESCs by the combination with the CRISPR/Cas system. Co-electroporation of Cas9 plasmid, single guide RNA plasmid and hKAT II KI vector increased the number of drug-resistant colonies and greatly enhanced the HR efficiency from 0 to 36 %. All the clones which we obtained showed the same sequence as designed. These recombinant clones resulted in chimeras that transmitted the hKAT II KI allele to their offspring. hKAT II KI rats showed no reduction of KATs mRNA expression and the amount of kynurenic acid was similar between the hKAT II KI rats and the wild type in their brains. These results indicate that the methodology presented in this report can overcome the problem encountered in conventional gene-targeting that prevented production of humanized rats.

We report on the characterization of volume holographic gratings recorded in photopolymerizable nanocomposites incorporated with hyperbranched polymer (HBP) acting as transporting organic nanoparticles. The HBP possesses ultrahigh index of refraction owing to the inclusion of triazine and aromatic ring units. Such an HBP was easy to disperse into acrylate monomer without any aggregation, so that films with good optical quality are available. A transmission volume grating with refractive index changes up to 2.3×10-2 was obtained at 27 vol.% HBP concentration and 7 vol.% multifunctional acrylate monomer at a wavelength of 532 nm.

The electrocatalysis of heat-treated Co-TPP/carbon for O 2 reduction and H 2 O 2 formation using a fuel cell reactor with an H 2 SO 4 aqueous electrolyte was studied (TPP: 5,10,15,20-tetrakis(phenyl)-21 H ,23 H -porphyrin). Carbon supports, including vapor grown carbon fiber (VGCF), activated carbon (AC), carbon black XC-72 (XC72), and carbon black Black-Pearl-2000/3500 (BP2000/3500), strongly affected the electrocatalysis of the Co-TPP/carbon. The Co-TPP/VGCF heat-treated at 1023 K, abbreviated as Co-TPP/VGCF(1073), showed a good electrocatalytic activity for H 2 O 2 formation (1.0 mol dm −3 with 40% current efficiency (CE)); however, other carbon supports were unfavorable. Electrocatalytic activities were Co-TPP/VGCF(1073) >> Co-TPP/XC72(1073) > Co-TPP/AC(1073) > Co-TPP/BP2000(1073). Their electrocatalysis were studied by rotating ring-disk electrode voltammetry and kinetic studies of the decomposition of H 2 O 2 and the electroreduction of H 2 O 2 to water. These studies indicated that the electrocatalytic activities for the successive reduction of H 2 O 2 to water determined the final H 2 O 2 concentrations and CEs. An active site of heat-treated Co-TPP/VGCF was characterized by X-ray photoelectron spectroscopy, and X-ray absorption near-edge fine structure spectroscopy. Partial pyrolysis of Co-TPP on the carbon surface was essential to generate the active site for the H 2 O 2 formation. A model of the Co active site, CoN 2 –carbon, was proposed.

Heat-treated MnCl–porphyrin supported on activated carbon (AC) catalyzed electrochemical reduction of O2 to H2O2 using an H2/O2 fuel cell reactor. Suitable preparation conditions for an Mn–porphyrin electrocatalyst were studied for the H2O2 formation, such as types of porphyrin rings, heat-treatment temperatures in He, and Mn loadings. The effects of reaction conditions, H2SO4 concentration, P(O2), P(H2), and electrolyte flow on the H2O2 formation were studied. Then, 0.5 wt % MnCl–TPP/AC heat treated at 823 K and 0.3 wt % MnCl–OEP/AC heat treated at 723 K showed good electrocatalytic activities for the H2O2 formation (TPP: 5,10,15,20-tetrakis(phenyl)-21H,23H-porphyrin, OEP: 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin). A maximum H2O2 concentration of 1.0 mol dm–3 with 47% current efficiency (CE) was obtained under suitable conditions. The heat-treated MnCl–TPP/AC and MnCl–OEP/AC electrocatalysts were characterized using temperature-programmed desorption, X-ray absorption near-edge structure spectrosco...

We developed chip-scale remote refractive index sensors based on Rhodamine 6G (R6G)-doped polymer micro-ring lasers. The chemical, temperature, and mechanical sturdiness of the fused-silica host guaranteed a flexible deployment of dye-doped polymers for refractive index sensing. The introduction of the dye as gain medium demonstrated the feasibility of remote sensing based on the free-space optics measurement setup. Compared to the R6G-doped TZ-001, the lasing behavior of R6G-doped SU-8 polymer micro-ring laser under an aqueous environment had a narrower spectrum linewidth, producing the minimum detectable refractive index change of 4 × 10-4 RIU. The maximum bulk refractive index sensitivity (BRIS) of 75 nm/RIU was obtained for SU-8 laser-based refractive index sensors. The economical, rapid, and simple realization of polymeric micro-scale whispering-gallery-mode (WGM) laser-based refractive index sensors will further expand pathways of static and dynamic remote environmental, chemical, biological, and bio-chemical sensing.

The fragmentative decomposition of ketone-suspended Ag2O micropowders (most preferably in acetone), induced by 1064 nm nanosecond laser irradiation as a single-pulse event at the required minimum laser fluence as low as ∼0.1 J/cm2, proved to offer a highly productive pathway to novel Ag nanoparticles (AgNPs) with many unique properties. The maximum NP production rate reached 2.5 mg/min at the input laser power of only ∼0.5 W, and the product AgNPs, typically 10−20 nm in diameter, exhibited excellent dispersity in ketone without any intentional addenda, thus being self-stabilized for concentrations up to ∼5 wt % (in acetone) or to more than 20 wt % (in γ-butyrolactone). The novelty of the present AgNPs was corroborated further by unusual properties that their film coatings manifested, such as a distinct coloring resembling that of bulk gold and a high electric conductivity gained by low-temperature (

The first example for transition metal catalyzed copolymerization of tetracyclododecene (TD) with styrene as well as of norbornene (NB) with styrene was achieved by the use of nickel(II) complex in the presence of MAO. High cyclic olefin contents of these copolymers were showed by 1H NMR measurements. Their GPC curves are all unimodal and Mw/Mn ratio of both homo- and copolymer samples are rather narrow value. These results show that these homo- and copolymerization take place at a single active site. The cyclic olefin content in these copolymers could be changed by changing the comonomer feed ratio. TD/styrene copolymers showed higher Tg value than that for NB/styrene copolymers and the Tg value were increases with an increase of TD content. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Various polygonal tubes were compressed in the axial direction under quasi-static and dynamic loading conditions. The effect of the polygonal shape and the wall thickness on the crush behavior is investigated, in which the cyclic buckling takes place. The numbers of polygonal edges were 3, 4, 5, 6 and 7 in the experiment. A circular tube was also tested for comparison. The tubes were machined from aluminum alloy A5056 bar. Crush strength is estimated as an index of the energy absorption capacity of the tube. It increases with increasing the number of polygonal edges of the tube, although it almost saturates when the number of polygonal edges is more than 6. For the wider variety of polygonal tubes than that in the experiment, numerical simulation is performed using the dynamic explicit finite element code DYNA3D. The computed crush behavior well agrees with the corresponding experimental one, however, the difference in collapse mode arises due to the slight imperfections in experiment. The deformation pattern becomes more irregular for the thinner-walled tube. Further, it is presumed that the large hardening exponent in the plastic property of the material could prevent the buckling switching from the symmetric mode to asymmetric one in the crushing of circular tube.

We report on the volume holographic grating formation in photopolymerizable polymer nanocomposites thatincorporate new hyperbranched polymers (HBPs) acting as transporting organic nanoparticles. Since HBPs areeasily dispersed to acrylate monomer without any aggregation and possesses ultrahigh index of refraction of theorder of 1.8 in the green due to the inclusion of triazine and aromatic ring units, volume gratings with goodoptical quality and refractive index changes as large as 2 .2 × 10 Š 2 can be recorded. It is also shown that theout-of-plane thickness change due to polymerization shrinkage is reduced to 2% or lower by the HBP dispersion.Keywords: photopolymers, holographic recording, nanoparticles, volume holograms, hyperbranched polymers 1. INTRODUCTION Holographic photopolymers have been investigated extensively for their use in photonics and information displaysuch as holographic memories, holographic optical elements, narrowband optical “lters, GRIN lens, electri-cally switchable Bragg gratings, and three-dimensional and headup/headmount displays.

The capability of mounting a parallel-optical module onto a PCB through solder-reflow process contributes to reduce the number of piece parts, simplify its assembly process, and minimize a foot print for both AOC and on-board applications. We introduce solder-reflow-capable parallel-optical modules employing 1060-nm InGaAs/GaAs VCSEL which leads to the advantages of realizing wider modulation bandwidth, longer transmission distance, and higher reliability. We demonstrate 4-channel parallel optical link performance operated at a bit stream of 28 Gb/s 2 31 -1 PRBS for each channel and transmitted through a 50-m-core MMF beyond 500 m. We also introduce a new mounting technology of paralleloptical module to realize maintaining good coupling and robust electrical connection during solder-reflow process between an optical module and a polymer-waveguide-embedded PCB.

The laser-induced fragmentation of thin Au and Ag flakes in acetone by 1064-nm nanosecond laser (with the fluence typically ∼2 J/cm2) potentially offers a highly productive pathway to stable metal nanoparticles in liquid. Acetone serves as a superior liquid medium that keeps fine metal nanoparticles free from precipitation even in such concentrated nanoparticle solutions exceeding ∼0.1 M. Thin metal flakes have good capability to absorb the 1064-nm laser energy as efficiently as in the visible region. A part of the thus laser-heated molten flakes explosively split into submicroparticles, and some other significant part directly into fine nanoparticles. Both kinds of product particles have minor absorption cross-sections for subsequent laser pulses at 1064 nm, and thus no longer fragment further. One of the two kinds of Ag flakes studied in this work yielded fine Ag nanoparticles at a remarkable high production rate of 1.1 mg/min for the input laser power of only ∼0.65 W.

We developed a chip-scale temperature sensor with a high sensitivity of 228.6 pm/°C based on a rhodamine 6G (R6G)-doped SU-8 whispering gallery mode microring laser. The optical mode was largely distributed in a polymer core layer with a 30 μm height that provided detection sensitivity, and the chemically robust fused-silica microring resonator host platform guaranteed its versatility for investigating different functional polymer materials with different refractive indices. As a proof of concept, a dye-doped hyperbranched polymer (TZ-001) microring laser-based temperature sensor was simultaneously developed on the same host wafer and characterized using a free-space optics measurement setup. Compared to TZ-001, the SU-8 polymer microring laser had a lower lasing threshold and a better photostability. The R6G-doped SU-8 polymer microring laser demonstrated greater adaptability as a high-performance temperature-sensing element. In addition to the sensitivity, the temperature resolutions for the laser-based...

Growth or curtail of spall damage in aluminum plates under repeated impacts has been monitored with a C-scan acoustic microscope (C-SAM) and a PVDF focused transducer. The spall damage or ductile voids were formed by plate impact tests using a gas gun which has a special recovery unit for target plates. The target plate has been impacted up to a maximum of three times with velocities ranging from 100m/s to 200m/s. This experiment has revealed the following: (1) From the C-scan and B-scan images of the spall damage, we can observe the change in three dimensional distribution of voids in aluminum plates under repeated impact. (2) When the second impact stress is higher than the first, which is greater than the spall threshold stress, the voids grow in size and number. (3) On the contrary, a part of voids disappear when the first impact stress is higher than the second, only if the latter is greater than some critical value. (4) The B- and C-scan images overestimate the void size when the voids are less than the ultrasonic beam diameter in size at the focus and are aligned closely in a plane. (5) The changes in B- and C-scan images under repeated impact are well correlated with the change in attenuation (amplitude change of B2 to B1 echo).

We demonstrate a novel architecture of mounting parallel-optical modules (POMs) onto an optical printed circuit board (PCB) through Sn-Ag-Cu-solder reflow process where precisely positioned stud-pins on optical PCB and guide holes formed on POMs were mated to maintain good optical coupling. We confirmed that fabricated 14-Gb/s × 12-channel POMs achieved a good transmission performance on a test environment using evaluation boards. Then, the POM was mounted onto the optical PCB through Sn-Ag-Cu-solder reflow process actually. We report coupling loss characteristics and signal qualities at 14-Gb/s PRBS 231-1 for the optical link using POM-mounted optical PCBs.

We report on volume holographic recording at a wavelength of 532 nm in photopolymerizable polymer nanocomposites that are incorporated with new hyperbranched polymers (HBPs) acting as transporting organic nanoparticles. Since HBPs possess an ultrahigh index of refraction of 1.82 due to the inclusion of triazine and aromatic ring units, high-contrast transmission volume holographic gratings with refractive index modulation amplitudes as large as 2.2×10(-2) are recorded. This value enables us to realize a 10 μm thick transmission volume grating with the diffraction efficiency near 100% in the green.

Alkynyliodonium salts can be directly prepared from alk-1-ynes by the reaction with iodosobenzene, tetrafluoroboric acid, and a catalytic amount of HgO.

48-fiber thermoplastic MT ferrule is developed. The fiber hole position error is below 2.5 μm and the insertion loss is below 0.5 dB. The ferrule is cost effective compared with conventional thermosetting ferrule.

Copolymerization of styrene derivatives, such as 4-tert-butylstyrene (4TBS), 4-methylstyrene (4MS), 4-methoxystyrene (4MOS), 4-bromostyrene (4BS), and 5-ethylidene-2-norbomene (ENB) was conducted with nickel (Ni) compound/methylaluminoxane (MAO) catalysts. Polymerization behaviors and properties of the resulting copolymers were investigated. Nickel bis(acetylacetonate) (1) / MAO showed the highest activity. Tg values of the obtained copolymers reached to ca. 300 °C.

Alkynyliodonium salts can be directly prepared from alk-1-ynes by the reaction with iodosobenzene, tetrafluoroboric acid, and a catalytic amount of HgO.